Despite extremely high arrest rates into young adulthood among chronic users of public child mental health systems (CMH population) little is known about the details of this offending. Targeted crime prevention efforts with this population would be beneficial because their arrest rate is high and they are accessible for prevention efforts by virtue of their system involvement. This study will examine lifetime within-individual longitudinal arrest patterns (criminal careers) to age 25 in the CMH population. This study will describe these criminal careers and their correlates, examine the impact of standard MH treatments on them, and directly compare criminal careers of CMH and non-CMH general offenders, all within gender. This will provide policymakers with knowledge about who offends, and when, practices to steer youth towards or away from, and a basis from which to decide whether practices based in the criminology literature of the general population applies well to the CMH population. The following are the Specific Aims of this study. 1. In a statewide study, describe different within-individual longitudinal arrest patterns and identify their individual, family, and socio-environmental correlates within the CMH population. 2. Examine the impact of standard MH services on justice system involvement patterns to the age of 25 among those in the CMH population. 3. Compare arrest patterns to the age of 25, between youth in the Child Mental Health System and youth in the general offending population. These areas will be investigated in the proposed study using a database that combines two statewide administrative data bases and Census tract information to generate individuals' demographic, clinical, family, and neighborhood characteristics, full lifetime arrest histories, and use of key mental health services for adolescent case management clients of the Massachusetts Department of Mental Health. It will also contain demographic and neighborhood characteristics, and lifetime arrest histories of a matched sample of general offenders. Our approach, which mixes the methods and perspectives of criminology and mental health services research, provides a solid platform for learning about the criminal careers of CMH youth, and guiding future research in this much-neglected area. [unreadable] [unreadable]